Finding the Third Proportional to 438,912 and 641,722.50

Step by Step Solution

1. Step 1: Write the proportion equation
   438,912 : 641,722.50 = 641,722.50 : x
2. Step 2: Convert to fraction form
   438,912/641,722.50 = 641,722.50/x
3. Step 3: Cross multiply
   438,912x = 641,722.50 × 641,722.50
4. Step 4: Simplify right side
   438,912x = 411,807,767,006.25
5. Step 5: Solve for x
   x = 411,807,767,006.25/438,912
6. Step 6: Final answer
   x = 938,246.77